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Efficacy of Piperaceous plant extracts in controlling chili anthracnose

Prissana Wiriyajitsomboon: Kasetsart University

<div>The development of biopesticides has been intensively researched since problems of environmental pollution, pathogen resistance, and residual toxicity due to the use of synthetic fungicides in agriculture have developed and been addressed. The objective of this research was to investigate the efficacy of crude extracts from Thai native plants in the genus <em>Piper</em> (Piperaceae) as an alternative to chemical fungicides in controlling chili anthracnose. The antifungal activity of crude extracts against <em>Colletotrichum capsici</em> was investigated <em>in vitro</em> and <em>in vivo</em>. Samples of plant extract from 14 species were screened against <em>C. capsici</em> at the concentration of 100000 ppm on an agar medium using the disc diffusion method (Heatley, 1944). The results showed that four plant extracts including P8 and P12 obtained from <em>P. kongkandanum, </em>and P14 and P15 obtained from <em>P. macropiper </em>inhibited the growth of the fungus<em>. </em> The crude extracts showing positive results were applied on ‘Jin da’ chili fruits at the concentration levels of 20000, 40000, 60000, 80000, and 100000 ppm prior to inoculation with a fungal mycelial disc. Three sets of controls were applied with sterile distilled water and azoxystrobin and the untreated fruits. Disease severity was assessed eight days post inoculation by measuring the lesion diameters. P12 and P15 crude extracts completely inhibited lesion development at 80000 and 40000 ppm, respectively. The activity of Piperaceous plant extracts against <em>C. capsici</em> may be useful at controlling anthracnose of chili production without chemical use.</div>